Aluminum chloride treatment of hydrocarbon oils



.S \\N N.

v. l. KoMAREwsKY. Erm.

Filed Sept. 12. 1940 ALUMINUM CHLORIDE TREATMENT OF I'IYDROCARBON OILS Patented Aug. 8, 1944 ALUMINUM-cameron TREATMENT or mRocAanoN oms Vasili I. Komarewsky and Lev A. Mekler,

Chicago,

lll., assignors to Universal Oil Products Company, Chicago, Ill., a corporation of Delaware Application September 12, 1940, Serial No. 356,458 6 Claims. (Cl. 260-683.5)

This invention` relates to 'the treatment of petroleum distillates heavier than` gasoline to produce therefrom substantial yields of iso-butane, motor fuels with high content of isoparafllns and other valuable products.

The process is particularly applicable to the treatment of gas oil distillates produced as intermediates in the distillation of crude oils but may.

also Ybe applied to treatment of other petroleum fractions. More particularly the process ofthe invention is concerned with the catalytic conversion of petroleum distillates boiling higher than gasoline by a continuous process to form high yields of isobutane, isopentane and high octane aviation gasoline.' y

Isobutane has become a material of great importance to the oil industry as the result of processes of comparatively recent development which are effective in converting it to isoparafns boiling within the range -of gasoline which are great- 1y in demand as fuels for airplane engines. 'I'he isobutane may be catalytically dehydrogenated to form iso-butene which may then be polymerized to form branch chain octenes which readily hydrogenate -to the corresponding iso-octanes. The isobutane also may be alkylated with oleilns using either thermal or catalytic processes to form isoparaiiins boiling within the range of aviation gasoline. Since isobutane commonly occurs in smaller yields than the normal compound, any process for augmenting its yield from petroleum is of great importance.

The process of this invention operates in several stages. In the first catalytic stage, the raw oil charging stock is treated with aluminum chloride plus a minor amount of hydrogen chloride under conditions suitable for the formation of normally gaseous products having a high content of isobutane. Th'e second catalytic stage uses as a charging stock the liquid product from the first stage together with a recycle material approximately of the same characteristics. In the second catalytic step liquid from the first. step together with recycle material of similar characteristics is treated with aluminum chloride under conditions suitable for the formation of predominantly gasoline boiling range hydrocarbons. These gasoline boiling rangehydrocarbons are then subjected to treatment with aluminum chloride and hydrogen chloride in a third step under conditions suitable for theisomerization of the remaining normal parafflns to isoparaillns. The

Vliquid residue from the second catalytic cracking step may be directed toa coke chamber to reduce tained from the coke chamber are fractionated into various fractions and returned to the system.

In one specific embodiment the -present inven,

tion comprises a process for the production of isobutane and a high octane motor fuel which comprises continuously charging a raw oil with anh-ydrcus aluminum chloride and hydrogen chloride to an externally heated reactor, establishing recirculation of said mixture and catalyst, said recirculated mixture being discharged against the heated surface of the reactor in the form of high velocity jets, the rate of circulation, time of contact and temperature being regulated to form substantial quantities of isobutane, continuously removing from said reactor a vaporous fraction comprising said isobutane and a liquid fraction containing aluminum chloride in suspension, charging said liquid fraction to a second externally heated reactorffor further reacting in the presence of aluminum chloride and hydrogen chloride, establishing recirculation of said liquid fraction and catalyst, said recirculated mixture being discharged against the heated surface of the second reactor in the form. of high velocity jets, the rate of recirculation, time of contact and temperature in said second reactor being regulated to form substantial quantities of a high octane substantially saturated motor fuel, continuously removing from said second reactor-'a vaporous fraction comprising said motor fuel and a liquid fraction containing catalyst in suspension, charging said liquid fraction containing the catalyst in suspension to a coking chamber to effect reductionof the non-volatile constituents thereof to coke, fractlonating the volatile prodf ucts evolved froxnthe coke chamber to separate a fraction comprising gasoline and normally gaseous products and a higher boiling liquid fraction, heating a portion of said higher boiling liquid fraction to eiect vaporization thereof, supy plying said heated vapors to the aforesaid coking the residueto coke. -'The volatile products ob- 55V chamber to supply heat to said chamber and to aid in the removal of the volatile constituentslof said coking chamber, fractionating the vapors evolved fromthe two reaction chambers to separate isobutane, gasoline, and a higher boiling liquid residue containing condensed aluminum chloride vapors in suspension, subjecting said gasoline to theaction of anhydrous aluminum chloride and hydrogen chloride under conditions suitable for the isomerization ofthe normal parailinic constituents thereof to isoparains and returning the aforesaid higher y.boiling liquid resi- 'due containing condensed aluminum chloride vapors to the second reactor for further reacting.

The accompanying drawing dlagrammatically illustrates one specific form of the apparatus wherein the process of our invention may be conducted, as well as other features hereinafter described.

Referring now to the drawing, charging stock for the process which may comprise a gas oil is supplied to the system through line I and after passing through valve 2 is directed by means of pump 3 into line 4 which discharges into reactor 5. Before discharging into the reactor, the charging stock` is commingled with anhydrous aluminum chloride and hydrogen chloride and with a recycle Vfraction obtained in a manner hereinafter set forth. The aluminum chloride and hydrogen chloride are introduced to the system by wayI of line 6 controlled by valve 1 from which the mixture enters pump 8 discharging into line 9 controlled by valve I0. The aluminum chloride may be supplied in a slurry of hydrocarbon oil, although a preferred method is to use a suiicient pressure and temperature to keep the aluminum` chloride in a molten state. Heating coil so disposed A'as to receive heat from furnace I2 discharges the aluminum chloride, together with hydrogen chloride at a temperature of the order of 40o-600 F. The portion of the heated catalyst needed for reactor passes through valve |4 located in line I3 from which it enters line 4 for commingling with the raw oil charging stock and the recycle liquid to form the combined feed for the reactor. Reactor 4 is provided with means for `a high degree of recirculation and agitation of the heated materials, said heated-materials being discharged against the surface of the reactor in a thin fast-moving film so as to lpre-` vent coagulation and deposition of the cokeforming materials on the Heated surfaces. Preferably the degree of recirculation is varied from inlet to outlet by either varying the number and size of the jets which produce the turbulence inside the reactor or by changing the depth of the pool of liquid inside the reactor or both to obtain a relatively quiescent zone near the outlet so as to permit the relative concentration of the heavier materials near the outlet and their removal from the reactor by the eiiiuent material. As is shown-in the drawing, a liquid fraction is removed f rom reactor 5 by way of line |5 and after passing through pump I6, a portion is removed the flow diagram. This mixture of vapors enters column 2|` which operates as a de-ethanizer. Light gaseous hydrocarbons, together with hydrogen formed in the process, remain undissolved in the absorption oil used in column 2| and are removed as an overhead product by way of line 22 controlled by valve 23. Absorbing column 2| is' equipped with heating coil 24 and the lower boiling hydrocarbons are fractionated from the heavier products in the lower portion of the column. The liquid removed from the bottom of column 2| contains the isobutane and higher boiling products formed in the process. It enters line 23 supplying pump 26 discharging into line 21 controlled by valve 23.- After passing through valve 28 this liquid enters debutanizing column 23' wherein an loverhead product containing the isobutane formed in the process, together with minor amounts of higher as well as lower boiling constituents, is removed as an overhead product by wav` of line 30 controlled by valve 3|. Debutanizing column 29 operates in the conventional manner, a portion of the overhead product being condensed and returned to the column as a reflux, although means for accomplishing this are not shown in the diagram. To prevent the possible plugging up of coolers and condensers' with the aluminum chloride that |passes on with the vapors, contact type condensers are preferably used in this process. In these condensers vapors are bubbled through a pool of the condensate, the latter being used as a cooling medium. A portion of the condensate is recirculated through a cooler to abstract the heat equal to that brought into the condenser by the vapors. In the operation of debutanizing column 29, a side cut comprising the gasoline formed in the process is removed by way of line 32 and' after.

passing through pump 33 enters line 34 controlled by valve 35 and enters heating coil 36 so disposed as to receive heat from furnace 31. The temperature of the heated gasoline leaving coil 36 lies within the approximate limits of 15o-500 F. It enters line 38 and isy directed to line 39 wherein it is commingled with a further supply of anhydrous aluminum chloride and hy,- drogen chloride andl then rpasses through valve 4|l entering column 4| which operates as a reby way of line 43 to a' second reactor for treatment as hereinafter set forth. 'I'he remainder and greater portion of the liquid discharging from pump I6 enters line I1 controlled by valve I8 and is returned to the reactor by being discharged into line 4. The quantity of aluminum chloride .supplied to reactor 5 may vary from 1/2 to 5% by weight of the charging stock. The amount of hydrogen chloride may be approximately 1/2 volume per cent Aof the charging stock. The temperature maintained in reactor l5 is of the order of 400-600 F. liteactor 5 isexternally heated in order to supply theheat absorbed in the'endothermic cracking reactions. maintained within the vreactor lies within the range of atmospheric to about 20o pounds per square inch and is preferably about 100 pounds per square inch. The liquid fraction recirculated by way of line I1 valve Il may be approximately 25-100 volumes of liquid per volume of raw oil charging stock.

The vaporous fraction evolved from reactor l actor for isomerization of normal paraillnic const ituents to isoparafiins. line is removed as an overhead product by way of line A2 controlled by valve 43. Column 4| isA equipped with heating coil 44 in which theheat needed for fractionating the gasoline from the higher boiling products is supplied; These higher boiling products formed in the isomerization reaction, together with suspended aluminum chloride, are removed from column 4| by way of line 45 and after passing through pump 43 are A discharged into line 41 controlled by valve 43 and directed to line |1 from which they are returned to primary reactorli.

boiling products may in part or all be directed from line 41 to line |02 controlled by valve |43 and discharged into line 68, wherein they become part of the recirculated liquid for secondary rel actor 65. l l

The liquid fraction removed from reactor l, together with the suspended aluminum chloride, is directed from line I1 into line 43 and after passing through valve 50 enters line 53 wherein it is commingled with the higher boiling liquid fraction 'obtained in debutanizing column 23. As shownA in\t he diagram, the higher boiling' fraction Obtained in'column 23 enters line 3| supplying The isomerized gaso=` If desired, these higher pump 52 which discharges into line 58 and after passing through valve 54 is'discharged into reactor 65. A portion or all of this higher boiling liquid may be directed from line 53 to line v|00 controlled by valve IOI and discharged into line I1 from which it is supplied to the primary reactor as shown in the drawing. A side-cut with an initial boiling point of approximately 200 F.' is removed from column 28 by way of line 55.fr om which it enters pump 56, discharging through line 51 into cooler 58' wherein it enters into indirect heat exchange with the liquid cooling medium supplied by Way of line valve 60`and removed by way of line 8| controlled by valve 62. This cooled naphtha fraction enters line 63 and, after passing through valve 54, is supplied to column 2| wherein it is used as an absorption medium. The secondary reactor 65 is operated in the same general manner as primary reactor 5. Itis provided with means for a high degree of recirculation and agitation of the heated materials, said heated materials being discharged against the surface of. the reactor in a l thin, fast-moving film so as to prevent coagulation and deposition of the rials on the heatedsurface. The degree of recirculation is so varied from inlet -to outlet by either varying the number and size of the jets which produce the turbulence inside the reactor or by change of the depth of a pool of liquid inside the reactor, or both, to obtain a relatively quiescent zone near the outlet so as to permit the relative concentration of the heavier matecoke-forming materials near the outlet andV their removal from thereactor by the emuent material. As is shown inthe drawing, a liquid fraction is removed from reactor 65 by way of line 68 and, after passing through pump 61, is divided into two portions. A portion of the stream is directed through line 88 and, after passing through valve 88 is returned to line 53 from which it is returned to the reaction zone. 'I'he additional supply of aluminum chlo.- ride and hydrogen chloride needed for reactor 85 is obtained by diverting a portion of the stream from line I3 to line 18 from which, after passing through tvalve 1I, it is supplied to'line 88 and commingled with the recycled stream for reactor 65. In cases where it might be desired to operate without a coking section of the process, a portion of the stream in line 88 containing used catalyst in suspension is removed from the system by Way of line 12 controlled by valve 18.

The temperature of the reacting materials in reactor 65'lies within the approximate limits oi' `400 to 800 F., while the utilizing pressures lie within the approximate limits of 100 to 300 pounds per square inch. The total quantity of aluminum chloride in suspension in the secondaryreactor 85 will vary from 2% to 8% by weight of the hydrocarbon oil. The amount of hydrogen chloride used is approximately one-half mol percent of the hydrocarbons. A vaporous fraction is continuously removed from the secondary reactor by way of line 14, controlled by valve 15, and is directed to line I8 for commingling with the vapors removed i'rom the primaryreactor, the resulting mixture being subjected to fractionationas hereinbefore set forth.

A portion of the liquid fraction removed from reactor 85 is directed through line 88 to line 18 from which, after passing through valve 11, it is directed to coking chamber 18. Coking chamber .18 operates in the conventional manner, the

evolved constituents formed therein being removed by way of line 18, controlled by valve 88,

59 throughl and directed to fractionator 8|. In column 8| gasoline and lower boiling products are removed as an overhead fraction by way of line 82 controlied by valve 83. This mixture of gasoline and lower boiling products is directed to line 14, being commingled with the vaporous fraction obtained ,from the .secondary reactor and then combined lwith the vapors from the primary reactor. The iinal mixture is directed to column 2 I for separation as indicated in the flow diagram. If desired,

the overhead fraction from column 8| may be retirely or in part, is directed vto line 81, controlled by valve 88, from which it is supplied to heating coil 88 so disposed as to receive heat fromi'urnace 88. 'I'he higher boiling liquid is vaporized in coilV 88, the heated -vapors leaving' by way of line 8| and after passing to cokingchamber 18. heated vapors is to supply heat to -the'coking chamber to assist in the removal of the volatile constituents formed in the coking operation. 'I'he and then supplied to 5 second reactor may be operated at a temperature in suspension,

heated vapors leaving coil 88 may be at a temperature of approximately l000 F. and at a. pressure'of about 100 poundsper square inch. If desired, a portion of this higher boiling liquid in line 88 may be directed to line 83 and removed from the system by way of valve 84 or, preferably, directed through valve 85 for recycling to the secondary reactor.

The ,following vexample illustrates the 4yields of the principal products obtainable in the normal operation of the process. While the data are characteristic, they are not introduced with the intent of unduly limiting the proper scope oi' the invention.

The results obtainable inthe case of a Trini- 4 dad gasoil are used in the illustration. 'I'he gas oil 'has a 30.0 A. P. I. gravityand a boiling point range of 460-470 F. This stock may be charged to the rst reactor with 2% by weight of the aluminum chloride and one-half mol hydrogen chloride per hundred mols of oil, said reactor operating under a. pressure of pounds per square inch and at a temperature of 450 F. and using a 'time of contact such that 35% by volume is distilled from the reactor. 'I'he unconverted oil which comprises 65% by volume of theA charging stock may then be commingled with 11/2% by weight of aluminum chloride and one-half mol of hydrogen chloride per hundred mols of oil the second reactor. This of 650 F. and a, pressure of 100 pounds per square inch and with a time ofkcontact such that 46% by volume ofthe original stock is removed as a vapor. 'I'he liquid residue from the second reactor, containing the used aluminum chloride may then be discharged into a coking chamber and reduced to coke. A further quantity of volatile material is formed in the coking process which is then fractionated and the fractionsreturnedv to the corresponding parts of the process. Byoperating the `isomeriaation step at a pressure of 500 pounds per square inch and a temperature of C., the total quantity of aviation fuel produced may be 45 volume percent .of the charge.

81 by C. F. R. motor method while the bromine through valve .82 are supplied The function of these Its octane number may becontinuously charging a hydrocarbon oil with anhydrous aluminum chloride and hydrogen chloride to a reactor, establishing recirculation of admixed oil and catalyst, the rate of recirculation, time of contact and temperature being regulated to form substantial quantities of isobutane, continuously removing from said reactor a vaporous fraction comprising said iso-butane and a liquid fraction containing the catalyst in suspension, charging said liquid containing aluminum chloride in suspension .to a second reactor, establishing recirculation of said liquid.

fraction and catalyst, the rate of recirculation, time of contact and temperature in said second reactor being regulated to form substantial quantities of a high octane motor fuel, continuously removing from said second reactor a vaporous fraction comprising said motor fuel and a liq- 'uid fraction containing the used catalystvin susv pension, commingling the va'pors from the two reaction chambers and separating from them'a liquid fraction of the motor fuel boiling range and subjecting the last-named liquid fraction to the action of anhydrous aluminum chloride and hydrogen chloride under conditions suitable for the isomerization of substantial quantities of the 'normal paraillnic constituents thereof to form iso-paramns.

2. A process for the production of iso-butano and a high octane motor fuel, continuously charging a hydrocarbon oil with anhydrous aluminum chloride and hydrogen chloride to a reactor, establishing recirculation of admixed oil and catalyst, the rate of recirculation, time of contact and temperature being regulated to form substantial quantities of iso-butene, continuously removing from saidreactor a vaporous fraction comprising said iso-butane and a liquid fraction containing catalyst in suspension, charging said liquid fraction containing aluminum chloride in suspension to a second reactor, establishing recirculation of said liquid fraction and catalyst, the rate of recirculation, time of contact and temperature in said second reactor being regulated to form substantial quantities of a high octane motor fuel, continuously removing from said second reactor a vaporous fraction comprising said motor fuel and a liquid fraction containing the used catalyst in suspension, charging said liquid fraction containing the used catalyst in suspension to a coking chamber to effect reduction of the non-volatile constituents thereof to coke', fractionating the volatile products evolved from the coking chamber to separate a fraction comprising gasoline and normally gaseous prod'- ucts and a higher boiling liquid fraction, commingling said fraction comprising gasoline and normally gaseous products with the vapors evolved from the two reactors, fractionating said mixture to separate iso-butane and a liquid-fraction of the motor fuel boiling range, subjecting said liquid fraction of the motor fuel boiling range to the action of anhydrous aluminum chloride and hydrogen chloride under conditions suitable for the isomerization of substantial quantities of the normal parafllnic constituents thereof to form iso-paraillns.

3. A-process for the production of iso-butane and a high octane motor fuel which comprises,

continuously charging hydrocarbon oil with .anhydrous aluminum chloride and hydrogen chloride to a reactor, establishing recirculation of admixed oil and catalyst, the rate of recirculation, time of contact and temperature being regulated to form substantial quantities of iso-butane, continuously removing from said reactor a vaporous fraction comprising said iso-butane and a liquid fraction containing catalyst in suspension, charging said liquid fraction containing aluminum chloride in suspension to a second reactor, establishing recirculation of said liquid fraction and catalyst, the rate of recirculation, time of contact and temperature in saidv second reactor being regulated to form substantial quantities of a high octane motor fuel, continuously removing from said secondary reactor a vaporous fraction comprising said motor fuel and a liquid fraction containing the lused catalyst in suspension, commingling the vapors from the two reaction chambers and separating from them a liquid fraction of the motor fuel boiling range and a higher boiling liquid fraction containing condensed aluminum chloride vapors in suspension, charging said higher Iboiling liquid fraction with suspended aluminum chloride to the second reactor for treatment as hereinbefore set forth and subjecting the aforesaid liquid fraction of the motor fuel boiling range to the action of anhydrous aluminum chloride and hydrogen chloride under conditions suitable for the isomerization of substantial quantities of the normal parafllnic constituents thereof to form iso-parafns.

4. A process for the production of iso-butane and a high octane motor fuel which comprises, continuouslycharging hydrocarbon oil with anhydrous aluminum chloride and hydrogen chloride to a reactor, establishing recirculation -of admixed oil and catalyst, the rate of recirculation, time of contact and temperature being regulated to form substantial quantities of isobutane, continously removing from said reactor a vaporous fraction comprising said iso-butane and a liquid fraction containing catalyst in suspension, charging said liquid fraction containing aluminum chloride in suspension to a second reactor, establishing recirculation of said liquid fraction and catalyst, the rate of recirculation, time of contact and temperature in said second reactor being regulated to form substantial quantitiesA of a high octaneV motor fuel, continuously removing from said second reactor a vaporous fraction comprising said motor fuel and a higher `:fraction of the motor fuel boiling range and a higher boiling liquid fraction containing condensed aluminum chloride vapors in suspension, charging said higher boiling liquid fraction with condensed aluminum chloride vapors to the second reactor for treatment as hereinbefore set forth and subjecting the aforesaid liquid fraction of the motor fuel boiling range to the action of anhydrous aluminum chloride and hyassigne drogen chloride under conditions suitable i'or the isomeu'ization of substantial quantities of the normal paralnic constituents -thereot to form iso-Walns.

5. A conversion process which comprises sub- Jecting hydrocarbon oil to the action of aluminum chloride under isobutane-producing conditions. separating vapors and liquid, subjecting the liquid to the further action of aluminum chloride under gasoline-forming conditions. commingling vaporous products of the last-mentioned step with said vapors, fractionating the resultant mixture to separate therefrom a fraction containing isobutane and a condensate containing gasoline fractions. and subjecting said condensate to isomerization in the presence of additional aluminum chloride.

6. A conversion process whichcomprises subjecting hydrocarbon oil to the action of aluminum chloride under isobutane-producing conditions, separating vapors and liquid; subiecting the liquid to the further action of aluminum chloride under gasoline-forming conditions, commingling vaporous products of the last-mentioned step with said vapors, tractionating the resultant mixture to separate therefrom a iraction containing isobutane and a condensate containing gasoline fractions, and subjecting said condensate to isomerization in the presence vof additional aluminum chloride, removing residual liquid from the second-mentioned aluminum chloride treatment and reducing the same to vaan.: I. Komanwsxr. Lav A. mummia..v i 

